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%I #7 Feb 21 2019 23:15:40
%S 1117,1151,1171,1181,1511,1777,1811,1999,2111,2221,2333,2777,2999,
%T 3313,3323,3331,3343,3373,3433,3533,3733,3833,4111,4441,4447,4999,
%U 5333,5557,6661,7177,7333,7477,7577,7717,7727,7757,7877,8111,8887,8999,9199,9929
%N Primes with at least one digit appearing exactly three times in the decimal expansion.
%C Sequence is probably infinite.
%e 2333, 3313, 3833 all repeat some digit 3 three times.
%p isdgctm := proc(n,d) local dgs,a,i ; dgs := convert(n,base,10) ; a := [seq(0,j=0..9)] ;
%p for i in dgs do a := subsop(i+1=op(i+1,a)+1,a) ; od: if convert(a,set) intersect {d} <> {} then true; else false; fi; end:
%p for n from 1 to 2000 do p := ithprime(n) ; if isdgctm(p,3) then printf("%d,",p) ; fi; od: # _R. J. Mathar_, Jun 21 2009
%Y Cf. A161786, A161796.
%K nonn,base
%O 1,1
%A _Ki Punches_, Jun 20 2009
%E Edited and corrected by _R. J. Mathar_, Jun 21 2009
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